Self-separating vibratory finishing apparatus

ABSTRACT

A self-separating vibratory finishing apparatus has an annular trough which is vibrated by a reversible motor having two eccentric weights, one of which leads or lags the other weight by a controlled angle automatically during rotation in each sense of rotation. A mass made up of workpieces and abrasive material effects a helical shifting motion in the direction opposite to the direction of motor rotation so that workpieces are surface finished. For separation purposes, a flap is moved downwardly into the mass in a direction so that the mass pushes it down. The mass overflows the flap onto a sieve, being aided by a flash gate having a special shape vertically positioned in the flowing mass upstream of the flap. The trough can also be helical and have a plurality of such gates disposed at intervals along the helical trough to permit the mass to ascend the trough for separation purposes.

[451 May21, 1974 [5 SELF-SEPARATING VIBRATORY FI ISHING nPARATUs [75] Inventor: Hisamine Kobayashi, Nagoya,

Japan [73] Assignee: KabushikiKaisha Shikishima Tipton ljagoya, Aichi, Japan [22] Filed: Nov. 2, 1970 [21] Appl. No.: 86,161

Related US. Application Data [63] Continuation-impart of Ser. No. 787,534, Dec. 27,

[30] Foreign Application Priority Data 1/1972 Rise 51/163 3,618,267 11/1971 Hulner 51/163 3,423,884 l/1969 Balz 51/163 Primary ExaminerHaro1d D. Whitehead Attorney, Agent, or Firm-Wenderoth, Lind Ponack [5 7] ABSTRACT A self-separating vibratory finishing apparatus has an annular trough which is vibrated by a reversible motor having two eccentric weights, one of which leads or lags the other weight by a controlled angle automatically during rotation in each sense of rotation. A mass made up of workpieces and abrasive material effects a helical shifting motion in the direction opposite to the direction of motor rotation so that workpieces are surface finished. For separation purposes, a flap is moved downwardly into the mass in a direction so that the mass pushes it down. The mass overflows the flap onto a sieve, being aided by a flash gate having a special shape vertically positioned in the flowing mass upstream of the flap. The trough can also be helical and have a plurality of such gates disposed at intervals along the helical trough to permit the mass to ascend the trough for separation purposes.

7 Claims, 14 Drawing Figures PATENTEBIAYZ! 1114 SHEU 1 BF 5 FIG.I

INVENTOR 2 HISAMINE KOBAYASHI BY f/Wwi,

ATTORNEYS PATENTEDIAYZI m4 3811.231

SHEEI 2 0F 5 FIG. 5

INVENTOR HISAMINE KOBAYASHI ATTORNEYS PATENTEDIAYZI 1914 $81 1.231

SHEET 3 BF 5 INVENT OR & FIG. 9 HISAMINE KOBAYASH] BY dd ATTORNEYS PATENTEDIAY 21 I974 3 L81 231 sum u or 5 FIG. IO

FIG. II a INVENTOR H l SAM lNE KOBAYAS H1 ATTORNEYS PATENTEDHAY 2 v :91: 3. 8 l 1 23 l' SHEET 5 BF 5 INVENTOR HISAM INE KQBAYASHI ATTORNEYS SELF-SEPARATING VIBRATORY FINISHING APPARATUS This application is a continuation-in-part of applica tion Ser. No. 787,534, filed Dec. 27, 1968 now abandoned.

BACKGROUND OF THE INVENTION This invention relates to improvements in a selfseparating vibratory finishing apparatus having a circularly annular or helical trough in which a mass consisting of workpieces and abrasives is subject to a helical finishing motion as it advances along the trough, and after the completion of the particular finishing operation, the mass is transported to a separation zone where the finished workpieces are automatically separated from the abrasives to be discharged without the necessity of rotating, inverting or otherwise moving the trough.

The vibratory finishing apparatuses of the type referred to have proved efficient and economical in operation, but they are inconvenient in that the said helical finishing motion is generally caused to take place in only one direction within the trough because the separator which is used requires a definite direction of mass flow. This can cause a relatively large workpiece to be finished unevenly.

Further, in order to transfer a mass to a separator, such as a sieve, after the completion of the particular finishing operation, attendant operations have heretofore been necessary. For example, a curved channel of semi-circular cross-section, sometimes called a spiral ramp, can be detachably inserted into the associated trough to raise the mass onto the sieve. This requires hard labor and is time consuming. Alternatively, a'large sized spiral ramp can be fixedly disposed within the trough. That portion of the trough occupied by such a ramp serves only as a transporting section for the mass, and this can decrease the finishing capability of the trough as much as 50%. Also upon falling from the top of the ramp onto the bottom of the trough, the mass is subject to impact, thereby causing many percussion marks on the finished workpieces.

Also there have been used various types of dam plates. For example, a dam plate can be fixedly secured to the bottom of the associated trough, and when it is desired to separate the finished workpieces from the mass, the dam plate has a sieve mounted thereon. This measure impedesthe stream of flowing mass so that the dynamic pressure exerted by the mass varies, whereby workpieces are often unevenly finished. Also, the workpieces in the mass falling from the dam means can have percussion marks made thereon. Alternatively, a dam plate can be provided which is raised from the bottom into the interior of the trough only when separation is effected. This measure causes the raised plate to be very steeply tilted as compared to the spiral ramp, as above described, with the result that it is difficult to conduct the separating operation.

Even if the operation of the spiral ramp or the dam plates is partly automated by using electrical or hydraulic means, a great amount of power will be required and also the associated machinery is apt to be damaged.

In addition, self-separating vibratory finishing apparatuses have been known which have a helical trough, the uppermost portion of which has a stationary dam plate provided on the bottom thereof. For carrying out separation, the plate is operatively connected to the associated sieve by a damper. Such arrangements are almost identical in effect to the arrangement including a single arcuate trough, and it is possible to transfer a mass composed of spherical abrasives and spherical workpieces to the associated sieve for separation purpose only with difficulty.

SUMMARY'OF THE INVENTION Accordingly, it is an object of the invention to provide a new and improved self-separating vibratory finishing apparatus in which the entire working volume of an arcuate trough is utilized to uniformly surface-finish workpieces and in which a mass can readily be transferred onto separation means disposed on the trough to remove and deliver all the finished workpieces from the mass, even though workpieces are a high proportion of the mass.

It is another object of the invention to provide a new and improved self-separating vibratory finishing apparatus in which the particular finishing operation is directly followed by a succeeding separation operation, upon the completion of which the apparatus is immediately ready for performing a succeeding finishing operation without the necessity of rotating, inverting or otherwise moving the finishing trough between the operations.

The invention accomplishes the above and other objects by the provisions of a self-separating vibratory finishing apparatus comprising an arcuate trough, a mass within the trough including workpieces to be finished, a vertical type electric motor including a pair of eccentric weights to vibrate the trough, a flap member and separation means disposed on the trough, the mass being capable of being transferred from the trough into the separation means over the flap member. The elec tric motor is a reversible type, and one of the eccentric weights is arranged to lead the other eccentric weight by a controlled angle during rotation of the motor in each sense of rotation, the vibrational movement of the trough causing the mass to effect a helical motion shifting in thedirection opposite to the direction of rotation of the motor. The flap member is positioned above the mass in its inoperative position during the finishing operation and in its operative position it engages the internal wall surface of the trough to block the moving mass, the flap member being responsive to the moving mass to selectively occupy the inoperative and operative positions.

Preferably, a vertical flash gate member is removably disposed in the trough upstream of the flap member to raise the level of the flowing mass between the members.

Advantageously, the pair of eccentric weights can be mounted on the electric motor on both ends of the shaft so as to be displaceable through different angles, respectively. If desired, one of the eccentric weights can be fixedly mounted on the shaft of the motor.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will become more readily apparent from the following detailed description taken in con- I junction with the accompanying drawings, in which:

' trough of the apparatus shown in FIGS. 1 and 2 taken along the line IIIIII of FIG. 2;

FIG. 4 is a view similar to FIG. 3, but illustrating a section taken along the line IV-IV of FIG. 2;

FIG. 5 is a fragmental developed sectional view taken along the line V-V of FIG. 2 and looking in the direction of the arrow;

FIG. 6 is a fragmental top plan view, partly in section, of a vibration generating device constructed in accordance with the principles of the invention;

FIG. 7 is a view similar to FIG. 6, but illustrating the lower end portion of the vibration generating device;

FIG. 8 is a fragmental side eievational view of the device shown in FIG. 7;

FIG. 9 is a diagrammatic view for explaining the operation of the device shown in FIGS. 6-8;

FIG. 10 is a side elevational view of another vibration generating device constructed in accordance with the principles of the invention with parts illustrated in section and parts broken away;

FIG. 11 is a plan view of the device shown in FIG. 10;

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. I, a finishing apparatus is shownwhich has a hollow pedestal 10 disposed on a foundation (not shown) on a plurality of short legs 12 of any suitable shock absorbing material such as rubber and fixed to the bottom thereof, and a cover 14 enclosing a pluarlity of helical springs 16 fixed at one end to the top of the pedestal I0 and disposed at substantially equal angular intervals around a central axis of said pedestal. A horizontal base flange 18 is rigidly secured to the other ends of the helical springs 16.

Rigidly secured to the base flange 18 is a vibratory finishing tub generally designated by the reference numeral 20 including a vibratory finishing trough 22 in the form of a toroid having a hollow circular annulus defined by a pair of coaxial cylinders open at the top and having the bottom 24 of semi-circular cross-section rigidly secured in a substantially horizontal position to the base flange 18. A cylindrical housing 26 extends through the hollow central portion of trough 22 being sealed thereto, and extends through the base flange and cover 18 and 14, respectively, into the pedestal 10. The cylindrical housing 26 has fixed to the lower end portion of the interior thereof a vibration generating unit generally designated by the reference numeral 28 and is constructed as will be more fully described hereinafter.

As best shown in FIG. 2, a sieve 30 is fixedly secured to the top face of the trough 22 so as to fully cover one portionthereof. The sieve 30 has a peripheral ridge 32 ally across the trough 22 at 32a. A portion of the ridge 32 along the outer periphery of the sieve 30 spaced from the one end extends outwardly of the trough to provide a discharge port 34. Starting at the other end of the sieve 30 radially traversing the trough 22, the outer side wall of the trough has an extension 35 curving upwardly and inwardly with the vertical dimension of the extension 35 gradually decreasing from a maximum adjacent said sieve 30 to zero adjacent the discharge port 34. A cover plate 36 is detachably disposed on the top surface of the trough 22.

A stationary rod 38'extends radially across the trough 22 so as to abut against the said other end of the sieve 30 on which no ridge is provided and a rockable flap 40 is pivotably mounted on the rod 38 to a horizontal position where it is inoperative. It has a length slightly greater than the vertical dimension from rod 38 to the bottom of trough 22 so that when it is rotated to a pendent position it is tilted at a predetermined angle to the horizontal and is operative, as will be more fully described hereinafter. The flap 40 has a profile such that in the pendent position the peripheral edge thereof is engaged with the internal wall surface of the trough 22 to provide a bulkhead in the trough. The flap 40 has a guiding flat protrusion 42 disposed on the upper half of that portion near the inner side trough wall and on the face thereof remote from the sieve 30 for a purpose which will be described hereinafter. The protrusion 42 has a lower arcuate end.

The vibration generating unit 28 will now be described with reference to FIG. 1 and FIGS. 6-9. The unit 28 comprises a reversible electric motor 44 vertically disposed within the cylindrical housing 26 and having a mounting flange 46 rigidly secured to a mounting annulus 48 which is, in turn, fixed to the lower portion of the inner wall surface of the housing 26 (see FIG. 1). The motor 44 has an output shaft 50 projecting beyond both ends of the motor housing. Each of the projecting end portions of the shaft 50 is stepped and is provided with one eccentric weight 52 or 54. At least one of the eccentric weights 52 or 54 is disposed on the motor shaft 50 for displacement about the axis thereof. To this end the shaft 50 can have keyed by key 56 to each end an exchangeable sleeve 58 provided with a circumferential groove 60 extending a predetermined distance around the periphery of the sleeve, as shown in FIGS. 6 and 7. Both the grooves can have the circumferential lengths equal to or different from each other. The eccentric weight 52 or 54 is mounted on the associated sleeve 58 by the hub 62 being rotatably fitted onto the sleeve and having a control pawl 64 on the hub extending into the associated groove 60. The other of the weights 52 or 54 can be fixed on the shaft 50 by a set screw 66 extending through the hub and paw] until it is screw threaded into the sleeve. If desired, both the weights can be disposed about the axis of the shaft 50 for displacement about the axis thereof. In order to fix either one of the upper or lower eccentric weights 52 and 54 on the rotary shaft 50, the weight can be stepped and the set screw 66 can extend through the portion thereof between the steps, as shown in FIG. 8. Alternatively, the weight can be flat and the set screw can extend through one of the longitudinal edges thereof.

In order to prevent each weight from falling from the shaft, the same is preferably sandwiched between two washers 68 and then secured on the shaft 50 by a set screw 70, as shown in FIG. 8.

FIGS. 6 and 7 illustrate the upper and lower eccentric weights 52 and 54 fixed on the shaft 50 with their respective positions shown in solid lines at 52 and 54, respectively, only for the purpose of explanation.

Also, as shown in FIG. 8, one or more additional weights 72 can be secured to the eccentric weight by screws in order to adjust its mass.

If the upper weight 52 is rotatable with respect to the sleeve, it can be rotated in opposite directions through angles of b and a" as shown in FIG. 6, and if the lower weight 54 is rotatable about the axis of the associated sleeve 58, it can be rotated in the opposite directions through angles of (1" and c, as shown in FIG. 7.

If the lower weight 54 is rotatably disposed on the associated sleeve 60 and the upper weight 52 is fixedly disposed, rotation of the motor 44 in the direction of the arrow 68 or in the clockwise direction as viewed in FIGS. 6 and 7, inertia will cause the lower weight to move counter-clockwise relative to the motor shaft 50 to the position 54-], while upper weight 52 will remain in its position 52 relative to the shaft 50, as shown in FIGS. 7 and 9, with the result that the upper weight 52 leads the lower weight 54 by an angle c, as shown in FIG. 9. If the motor is rotated in the direction of the arrow 69 or in the counterclockwise direction, the reverse action takes place and the upper weight 52 leads the lower weight 54 by an angle d, as shown in FIG. 9.

On the contrary, if the upper weight 52 is rotatably mounted on the associated sleeve 58 while the lower weight 54 is fixedly disposed on the associated sleeve 60, then the lower weight 54 remains at its position 54, as shown in FIGS. 6 and 9, fixed with respect to the motor shaft, while the upper weight 52 is caused to move to position 52-1 or 52-2, depending on the direction of rotation, whereby the lower weight 54 leads the upper weight 52 by angle a" or b". Alternatively, with both the weights rotatable with respect to the motor shaft, an angle therebetween will be a-c or b-d" depending upon the direction of rotation of the motor.

It will be understood that the advance angle can be varied by changing the length of either of the grooves 60. To this end. the motor shaft may have keyed on either the upper or lower ends sleeves having a circumferential groove of any desired length.

Referring back to FIGS. 1-4, the vibration generating unit 28 is energized to forcedly vibrate the trough 22 to impart a motion to a mass 70 including workpieces and abrasives. The vibratory motion has two components, one of which causes the mass to move in an orbital path as shown by the arrows 72, 73 and 74, and the other of which causes the mass to travel linearly in a direction determined by the direction of rotation of the motor 44. Thus, the mass effects a helical motion. If the upper and lower eccentric weights 52 and 54 are maintained in superposed relationship during the operation ofthe motor 44, that is, if the said advance angle is zero, then the mass 70 effects an orbital motion along a nearly semi-circular path in the direction of the arrows 72, 73 and 73, shown in FIG. 3, and on each radial plane of trough 22. The direction in which the mass is moved is independent of the direction of rotation of the motor. However, it has been found that when there is an advance angle as described above, between the upper and lower eccentric weights 52 and 54, respectively, even though it is small, the motion imparted to the mass has two components. The first component causes the mass to move in an orbital path such as above described,- and the second component causes the mass to travel linearly in the direction opposite the direction of rotation of the motor 44. Thus, the mass effects a helical motion. For example, if the weights are rotated in the clockwise direction as viewed in FIG. 2, then the mass effects a helical motion 76 shifting in the direction of the arrow 77 (see FIG. 3), Le, counterclockwise as viewed in FIG. 2.- On the other hand, rotation of the motor and the upper and lower weights 52 and 54 in the counterclockwise direction will cause the mass to effect a helical motion 78 shifting in the direction of the arrow 79, i.e., clockwise.

Thus, it will be appreciated that the mass can effect a helical motion shifting either clockwise or counterclockwise in accordance with the direction of rotation of the motor. It is to be noted that the reversal of rotation of the motor is accompanied by a change of the advance angle between the upper and lower eccentric weights which is effective for reversing the direction in which the helical motion shifts, but which does not change the direction in which the mass effects the above-mentioned orbital motion.

It has been found that the advance angle between the weights should be in general greater than 0", but smaller than 180 with an advance angle of approximately 90 degrees yielding a maximum working efficiency. For the finishing operation it is preferred that the advance angle have a value ranging from 10 to 40 and the most preferred value is 15 to 30. For a separation operation, it is preferred that the angle have a value ranging from 70 to 140 and the most preferred value is to 105.

When the upper weight of the motor is disposed in the space encircled by the helical springs 16 or below that space as shown in FIG. 1, the lower weight must be arranged to lead the upper weight. Alternatively,

when the lower weight of the motor is disposed at a level equal to or above the helical springs as illustrated in FIGS. 12 and 13, the upper weight must be arranged to lead the lower weight.

As shown in FIGS. 3 and 4, the upper portion of the outer side wall of the trough 22 is at least partially curved inwardly in a circular are to aide in causing the above mentioned orbital motion of the mass In FIGS. 10 and 11 wherein the same reference numerals designate the components corresponding to or similar to those shown in FIGS. 6 to 9, there is illustrated a modification of the vibration generating unit 28. A lower eccentric weight 54 is keyed by key 56 to a rotary shaft 50 of a motor 44 and rigidly secured thereto by a locking bolt 70 screw threaded into the end of the shaft 50 through a washer 68 and a locking washer 68. An upper eccentric weight 52 is rotatably fitted into the end portion of the shaft 50 in a manner similar to that previously described in conjunction with FIG. 6 and is prevented from falling off the shaft 50 by having a locking bolt 70 screw threaded into the end of the shaft through a locking washer 68 and a cap 68".

'mass 70 effects the abovementioned helical motion entire working volume of the trough being effectively utilized to perform the particular finishing operation. If desired, the motor can be reversed to reverse the direction inwhich the helical motion shifts to continue the finishing operation.

During the vibration of the trough 22, that portion of the mass 70 near the bottom forcedly ascends firstthe internal surface of the arcuate bottom 24 and then the internal surface of the outer peripheral wall of the trough 22 in the directionof the arrows 72. Thereafter it turns in the direction of the arrow 73 to reach the uppermost surface 82 as shown in FIGS. 3 and 4. Those portions of the mass on and adjacent the surface 82 are substantially free of the vibration of the trough 22 and form a surface layer 84 flowing downwardly in the direction of the arrow 74 until the surface layer 84 abuts against the inner wall surface of the trough. Thereafter the mass flows along the arcuate bottom 24 of the trough 22 whereby it again follows the path just described. At the same time the mass is moved horizontally in the direction opposite to the direction of rotation of the motor to effect the helical motion as previously described. In FIG. 4 that portion of the mass below a lower broken line 70a is the part that forcedly ascends due to the vibration of the trough as above described and can be called the A portion,.while that portion thereof above the upper broken line 70b is what flows downwardly toward the inner wall of the trough due to its inertia and the gravitational force and which can be called the 8" portion. The portion of the mass between the lines provides a central portion around which the A" and 8'' portions effect the orbital motion and can be called the C portion.

The vibration'of the trough 22 is effectively transferred to the mass portion A which in turn effects an energetic motion. However, the mass portions B and C have transferred thereto a very small part of the vibration and effect motions readily affected by .various factors.

In order to cause'a satisfactory helical motion of 'mass, it has been found that the weight nearer to the helical spring 16 must exert a smaller centrifugal force than the other weight when there is a smaller advance angle between the eccentric weights 52 and 53, and that the centrifugal force caused by the weights must be nearly equal when there is a larger advance angle between two weights. I

After the completion of the particular finishing operation, the flap 40 is released so it can rotate into the trough 22 and the direction of motor rotation is adjusted to give-a helical motion to the mass so that the mass shifts in a direction in which the stream of flowing mass pushes the flap downstream, in the example illustrated, the clockwise direction as viewed in FIG. 2. Then the stream of the mass exerts a dynamic force upon the pendent flap tending to force it smoothly into the flowing mass until the flap is stably engaged at its 8 periphery against the internal wall surface of the trough 22. Thus the flap 40 blocks the stream of the mass.

vUnder these circumstances, the successive portions of the flowing mass abutting against the flap '40 forcedly ascend the tilted flap and are transferred to the sieve 30 where the finished workpieces are separated from the abrasives and then delivered in the direction of the arrow 34a through the delivery port 34 to the succeeding processing section (not shown). The abrasives fall through the sieve 30 into the trough 22. This constitutes the separation operation.

It has been found that the angle between the flap 40 and the horizontal is preferably on the order of If the angle'is smaller than this, the flowing mass can more readily ascend the flap, while if the angle is larger,

it is difficult for the mass to ascend the flap. It has also been found that an angle ranging from 40 to to the horizontal is suitable for practical purposes.

The use of conventional damplates generally permits a mass moveing within a helical motion to ascend a slope of at most 15 degrees to the horizontal. If the mass includes spherical components, it cannot ascend a slope exceeding 3. However, the provision of protrusion 42 on the flap 40 is especially effective for increasing the angle of the slope to the horizontal of the slope as above described.

As the separation operation as above described proceeds, the level of that portion of the mass adjacent to and upstream of the flap 40 gradually decreases until its level reaches a broken line 82a, 8212 starting with the top of the flap and slanting downwardly upstream of the flap. At that time the mass portion downstream of the flap 40 will be at a level 82c. The horizontal broken line 83 represents the level of the mass before the flap '40 sinks into the mass. It will be appreciated that after the mass has reached the level 82b, 82a it cannot be transferred onto the sieve 30 over the flap 40. The invention also provides means to raise this level 82b.

To this end, a flash gate is disposed upstream of the flap 40 and carried by supporting rod 92 radially traversing the width of the trough 22 as shown in FIG. 2. The gate 9 0is movable vertically, for example, by pneumatic or hydraulic piston-and-cylinder means secured'to the outer surface of the outer side wall of the trough, although such means are not illustrated in order to simplify the drawings. That is, the flash gate 90 has a normal raised position where his located above the stream of the mass and it does not impede the stream,

as shown in solid lines in FIGS. 4 and 5, and has a lowered position where it is partly submerged in the flowing mass as shown by dotted lines in FIGS. 1 and 5. The lowered position of the gate is vertically controllable by any suitable means (not shown). As the A portion of the mass effecting a strong helical motion is at a higher level adjacent the outer side wall of the trough than on the opposite part, the gate plate 90 has the portion at its lower edge near the outer side wall of the trough 22 recessed as compared with the remaining portion thereof, as best shown in FIGS. 1 and 4. Thus it will be appreciated that when flash gate 90 is at its lowered position, it does not interfere with the mass portion A", but effectively blocks the mass portions B" and C, ensuring that the latter mass portions are prevented from flowing in the reversed direction as shown by the arrow 86 after they have abutted against the flap 40.

After the flap 40 has sunk into the flowing mass, the flash gate 90 is moved to its lowered position as illustrated in dotted lines in FIGS. 1 and 5. Then the flowing mass is forced to be fed into a zone 94 between the flap 40 and the gate 90 through the gap formed between the lower edge of the gate 90 and the adjacent portion of the bottom of the trough 22, whereby the mass portion disposed between the flap and gate has the level of its upper surface raised, as shown by broken line 88a in FIG. 5, ensuring that the mass is readily transferred onto the sieve 30 over the flap 40. This force feed of the mass into the zone 94 continues until the level of the mass upstream of the gate 90 falls to the level of line 96 (see FIG. 5).

In the embodiment illustrated, after the portion of the flowing mass filling the zone 94 between the flap and gate has reached the level 82b, the amount of the mass remaining in the trough 22 decreases to approximately 50 percent of that initially charged into the trough. Under these circumstances, the position of the surface of the portion of the mass located outside the zone 94 is at the tilted broken line 96 and a line 96a, which is an extension of the line 96. This makes it possible to remove all the finished workpieces from the mass leaving only abrasives.

If desired, the flash gate 90 can be rotatably mounted on the rod 94 in the same manner as the flap 40. Also the flap 90 can be movable vertically as is the gate 90.

In general, the configuration of the workpieces and abrasives greatly affects the upper limit of the angle of the'slope above which the corresponding means cannot ascend the slope. For example, abrasives which are rhombic, trigonal prisms or pyramids, cubes, discs, stars or indefinitely shaped lumps tend to impart a rigidity to the associated mass which can, in turn, ascend relatively steep slopes. However, it is difficult for any mass including spherical abrasives to ascend the slopes. Therefore the conventional apparatus including a vertical dam plate is disadvantageous in that even with a mass which has considerable rigidity, the workpieces cannot be removed from the mass if they exceed percent by volume, and with spherical workpieces and- /or spherical abrasives, the slope which the associated mass can ascend must be kept at an extremely small angle to the horizontal, making it very difficult to remove the workpieces from the mass.

Further, with a high proportion of workpieces to abrasive, it is difficult to removal all the workpieces from the corresponding mass. Therefore, the conventional vibratory finishing processes have used masses including, by volume, from 1 to 6 parts of abrasives per one part of workpieces. Also, the conventional type of high efficiency finishing processes can use a mass including, by volume, from I to more than 4 parts of abrasive for one part of workpieces. Even after the quantity of the mass has reduced to from 70 to 50 percent of the initial quantity through the removal of the finished workpieces, the remaining mass should continue to ascend the associated dam plate in order to remove all the finished workpieces from the mass. With a mass including, by volume, from 1 to less than 4 parts of abrasive for one part of workpieces, this is impossible with conventional apparatus.

The provision of tlie flash gate QTEEaYdiE to the invention ensures that even with a mass including abrasives and workpieces in substantially equal amounts, all the finished workpieces are efiiciently removed from the mass. It has been found that the use of the flap 40 with the protrusion 42 alone makes possible excellent separation from a mass including, by volume, about} parts or more of abrasives per one part of workpieces.

Referring now to FIG. 12, the components corresponding to or similar to those shown in FIGS. 1 to 5 are designated by the same reference numerals plus 100. An arcuate trough 122 is provided which is substantially similar in cross-section to the trough 22 shown in FIGS. 1 to 4, and slightly longer than one turn of the corresponding helix with the end portions thereof overlapping each other. The trough 122 has a lower end closed by a detachable cover (not shown) and an upper end portion including a step from which extends a horizontal extension, the bottom of which is a sieve 130. The step 140 serves as a dam plate of conventional design. A reversible electric motor 144 is vertically disposed in the manner as previously described, but in a space encircled by the arcuate trough 122. The motor 144 has a lower eccentric weight 154 at substantially the same level as a plurality of helical springs 116. If desired, the weight 154 can be disposed above the springs 116.

In order that, during operation of the apparatus, a mass ascends the upwardly tilted trough while it effects the abovementioned helical motion, a plurality of flash gates such as previously described are removably disposed at appropriate intervals within the trough. Two of these gates 190 are illustrated in FIG. 12. The gate 190 is substantially identical to the gate 90. If desired, a plurality of the troughs 122 canbe disposed one above another to form a helical trough as shown in FIG. 13 wherein the components corresponding or similar to those shown in FIGS. 1-4 are designated by the same reference numerals plus 200. The helical trough 222 can have an upper end portion such as shown in FIG. 12. A reversible electric motor 244 is encircled by the helical trough 222 and has its lower eccentric weight 254 disposed above a plurality of helical springs 216. As in FIG. 12, a plurality of flash gates 290 are fixedly or removably disposed in spaced relationship along and within the trough 222. The gate 290 is also substantially identical in shape to the flash gate 90.

The arrangementsillustrated in FIGS. 12 and 13 are operated in the same manner as previously described in conjunction with FIGS. l-5. Specifically, a mass is forced to successively pass through gaps between the lower ends of the gates 190 or 290, and the opposed portions of the trough bottom to ascend the trough with the upper eccentric weight 252 leading the lower eccentric weight 254. After all the finished workpieces have been removed in the manner as previously described, the motor is reversed to permit the remaining mass to descend along the trough while it effects a helical motion such as previously described for the purpose of discharging it from the trough through the lower end which has been opened.

FIG. 14 shows a modification of the flash gate 90 as previously described. A supporting plate 94 disposed in a trough (not shown in FIG. 14) such as the trough 22, 122 or 222, has adjustably secured thereto a flash gate section 90' substantially identical in shape to the flash gate 90.

In summary, the flap is maintained in its horizontal position and the motor is driven in the desired direction to cause the particular mass to effect a helical motion shifting in the direction opposite to the direction of rotation of the motor, thereby to perform a finishing operation. If desired, the motor can be reversed to continue the finishing operation. After the completion of the particular finishing operation, the flap is lowered provided that the last helical motion is in a direction in which the flowing mass pushes the flap downstream. For example. in the first embodiment. the last helical motion is in the clockwise direction, as viewed in FIG. 2. On the contrary, if the last helical motion is in the counterclockwise direction, as viewed in FIG. 2, then the motor is reversed followed by lowering of the flap. The stream of flowing mass exerts a force upon the lowered flap tending to sink it into the mass until the flap engages the internal wall surface of the trough. Thereafter the flash gate is lowered to partially impede the stream of mass. Due to the gate having the special shape as previously described, the mass can be easily transferred onto the associated sieve where all the finished workpieces are removed from the mass and are delivered externally of the trough while the abrasives fall through the sieve into the trough. In the arrangement shown in FIGS. 1-5, after the completion of the removal operation, the motor is reversed to change the direction of helical motion. Then the flap automatically lifts under the action of the mass flowing in the counterclockwise direction, as viewed in FIG. 2, and is maintained in its horizontal position. Then the flash gate is lifted. Thus, the trough is ready for the succeeding finishing operation.

In the arrangements shown in FIGS. 12 and 13, after the completion of the removal operation, the motor is reversed and the lower end of the trough is opened. This permits the remaining mass consisting only of abrasives to be delivered from the trough resulting in readiness for the succeeding finishing operation.

While the invention has been illustrated and described in conjunction with a few preferred embodiments thereof, it is to be understood that numerous changes and modifications may be resorted to without departing from the spirit and scope of the invention.

What is claimed is: v i,

l. A self-separating vibratory finishing apparatus comprising, in combination, a generally horizontal arcuate trough means adapted to hold a mass comprised of a quantity of finishing materials and workpieces to be finished, reversible electric motor means mounted on said trough means and having a vertical rotor, weight means mounted on said rotor, the position of which is automatically changeable upon a change ofdirection of rotation of said motor means and acts during rotation thereof for vibrating said arcuate trough means to cause said mass to effect a helical motion and motion along said trough means in one direction for finishing during rotation of said motor means in one direction and vibrating said arcuate trough means to cause said mass to effect a different helical motion and motion along said trough means in the other direction for separation ofthe components of the mass during rotation of the motor means inthe other direction, sieve means to a generally horizontal position to permit free finishing movement of said mass along said trough, said flap being downwardly rotated by said mass during movement of said mass in said other direction from said generally horizontal position to said lowered position to block said trough means and intercept the movement of said mass along said trough means in said other direction and cause the mass .to be lifted up onto the sieve.

2. A self-separating vibratory finishing apparatus as claimed in claim 1 in which said rotor means has a shaft, and said weight means comprises a pair of eccentric weights, one mounted on each end of said shaft for limited rotary movement freely in both directions, reversal of rotation of said motor causing automatic shifting of said weights from one extreme rotated position thereof to the other extreme rotated position thereof.

upstream of said flap member relative to the movement of said mass in said other direction and movable on said trough means from an inoperative position above said mass to an operative position where said flash gate member is vertically disposed in the moving mass with a gap between the lower end thereof and the adjacent portion of the bottom of the trough means, said flash gate member having the lower edge recessed on that portion near the outer side wall of the trough means for partly blocking the moving mass.

S. A self-separating vibratory finishing apparatus as claimed in claim 4 in which said trough means is an annular trough means and there is a single flash gate member.

6. A self-separating vibratory finishing apparatus as claimed in claim 1 wherein said trough means has an open top and an outer side wall having one portion vertically disposed and the remaining portion inwardly curved over the trough defined by said trough means.

7. A self-separating vibratory finishing apparatus comprising, in combination, a helically coiled trough means having vertically spaced turns and adapted to hold a mass comprised of a quantity of finishing materials and workpieces to be finished, electric motor means mounted on said trough means and having a vertical rotor, weight means mounted on said rotor, which during rotation thereof for vibrating said arcuate trough means to cause said mass to effect a helical motion and motion along said trough means in the upward direction for finishing during rotation of said motor means, sieve means disposed on said arcuate trough to retain finished workpieces thereon while permitting the finishing material to fall into said trough means, and a plurality of flash gate members disposed in spaced relationship along said arcuate trough means with a gap formed between the lower end of each flash gate and the adjacent portions of the bottom of the trough 

1. A self-separating vibratory finishing apparatus comprising, in combination, a generally horizontal arcuate trough means adapted to hold a mass comprised of a quantity of finishing materials and workpieces to be finished, reversible electric motor means mounted on said trough means and having a vertical rotor, weight means mounted on said rotor, the position of which is automatically changeable upon a change of direction of rotation of said motor means and acts during rotation thereof for vibrating said arcuate trough means to cause said mass to effect a helical motion and motion along said trough means in one direction for finishing during rotation of said motor means in one direction and vibrating said arcuate trough means to cause said mass to effect a different helical motion and motion along said trough means in the other direction for separation of the components of the mass during rotation of the motor means in the other direction, sieve means disposed on said arcuate trough to retain finished workpieces thereon while permitting the finishing material to fall into said trough means, a flap member mounted adjacent to said sieve means for rotation around a horizontal axis and being upwardly rotated by said mass during movement of said mass in said one direction from a lowered position blocking said trough means to a generally horizontal position to permit free finishing movement of said mass along said Trough, said flap being downwardly rotated by said mass during movement of said mass in said other direction from said generally horizontal position to said lowered position to block said trough means and intercept the movement of said mass along said trough means in said other direction and cause the mass to be lifted up onto the sieve.
 2. A self-separating vibratory finishing apparatus as claimed in claim 1 in which said rotor means has a shaft, and said weight means comprises a pair of eccentric weights, one mounted on each end of said shaft for limited rotary movement freely in both directions, reversal of rotation of said motor causing automatic shifting of said weights from one extreme rotated position thereof to the other extreme rotated position thereof.
 3. A self-separating vibratory finishing apparatus as claimed in claim 1 wherein said lowered position of said flap member is at an angle of from 80 to 40 degrees to the horizontal.
 4. A self-separating vibratory finishing apparatus as claimed in claim 1 further comprising at least one flash gate member movably mounted on said trough means upstream of said flap member relative to the movement of said mass in said other direction and movable on said trough means from an inoperative position above said mass to an operative position where said flash gate member is vertically disposed in the moving mass with a gap between the lower end thereof and the adjacent portion of the bottom of the trough means, said flash gate member having the lower edge recessed on that portion near the outer side wall of the trough means for partly blocking the moving mass.
 5. A self-separating vibratory finishing apparatus as claimed in claim 4 in which said trough means is an annular trough means and there is a single flash gate member.
 6. A self-separating vibratory finishing apparatus as claimed in claim 1 wherein said trough means has an open top and an outer side wall having one portion vertically disposed and the remaining portion inwardly curved over the trough defined by said trough means.
 7. A self-separating vibratory finishing apparatus comprising, in combination, a helically coiled trough means having vertically spaced turns and adapted to hold a mass comprised of a quantity of finishing materials and workpieces to be finished, electric motor means mounted on said trough means and having a vertical rotor, weight means mounted on said rotor, which during rotation thereof for vibrating said arcuate trough means to cause said mass to effect a helical motion and motion along said trough means in the upward direction for finishing during rotation of said motor means, sieve means disposed on said arcuate trough to retain finished workpieces thereon while permitting the finishing material to fall into said trough means, and a plurality of flash gate members disposed in spaced relationship along said arcuate trough means with a gap formed between the lower end of each flash gate and the adjacent portions of the bottom of the trough means. 